The PTCR ceramic materials with composition of Ba(0.85-x)Ca(0.15)(Bi(1/2)Na(1/2))(x)TiO(3) have been synthesized in air and in N(2) atmosphere at 1350 square, respectively. In the XRD spectra, there appears three diffraction peaks in the range of 20 = 18-23 degrees and the Raman shift at 302.1 cm(-1) becomes weak when the samples are re-annealed at 1250 square in air. It is speculated that the ordered distribution of Ba, Ca, Na and Bi in A-site contributes to the new appeared diffraction peaks. The samples sintered in flowing N(2) display a relatively low room-temperature resistivity and the PTCR effect can be enhanced after re-annealing in air.